Process for the production of printing



Dec. 16, 1930. 'H. REN'C 1,785,210

PROCESS FOR THE PRODUCTION OF PRINTING Filed Dec. 22', 1928 Jwwmlioz Patented Dec. 16, 1930 UNITED STATES PATENT OFFICE HEINRICH RENCK, F HAMBURG, GERMANY by mixing minute particles of the concentrated metal with the printing colour in such a manner'that they are loosely composed with the latter. The efl'ect is that, each time the ductor roller passes over the plate, the metal loosely mixed up with the printing colour precipitates in those places which are already covered with the amalgam, so that the separation of the metal from the colour takes place during the printing process. The metal is therefore continuously deposited on the die whilst printing goes on, the consequence being that that portion of the surface of the plate which is deprived of printing colour is raised above that portion of it to which this does not apply and that the quantity of colour distributed by the ductor roller is deposited in recesses. From these recesses the paper obtains a .very much larger quantity of colouring matter, so that the results of the P printing are improved. Moreover, the printing process itself is only made possible by the permanent addition of the metal during the printing. It has been proved beyond doubt that the coat of amalgam on the printing plate is destroyed in a very brief space of time if there is any break in the deposition of 40 the metal which ought to go on uninterruptedly. Printing of large editions is quite out of the question in that way. The printing process is only made possible with the aid of the metal whichmust be added in minute particles. i

The invention is illustrated in the accompanying drawings, in which: Figure 1 is a sectional view illustrating the application of the picture to be printed. and the application of the amalgam. 1

-PROCESS FOR THE PRODUCTION OF PRINTING Application filed December 22, 1928, Serial No. 328,057, and in Germany March. 21, 1928.

Figure 2 is a similar view of a slightly modified form.

Figure 3 is a similar View indicating the absence of amalgam between the portions of the picture to be inked for reproduction. 7,

Figure 4'lS a diagrammatic view showing the application of the finely divided amalgam to the printing rolls.

The present invention concerns the proby means of any process, such as copying,

screen or printing, etc. The plate a is then covered with a layer of amalgam, for example mercury amalgam. Thereby, those portions 1) which are covered by the picture portions prevent the adherence with the amaI-- gam, whereas the free portions 0, which therefore are not covered by picture surfaces, undergo a firm adherence with the amalgam.

therefore, will act as printing elements,

whereas the amalgamated surfaces 0 will re-' e1 the color and therefore not reproduce an impression. i

Another form is shown in Figure 2. A flat plate a consisting, .for example, of brass, is covered with a coating which consists of amalgam-repelling metal. This layer is d, and by way of example consists of nickel. The picture e to be printed is again produced upon this layer of nickel d by any process whatever. Then the plate a, with the nickel layer and the picture 6 which has been provided upon the layer of nickel d, is inserted into a galvanic bath. In this bath the nickel is removed from those places where it is not covered by the picture 6, so that at these portions f (see Figure 3) the brass of the plate (1 becomes exposed. Then the plate is coated with amalgam and the amalgam adheres firm ly to the plate a only at the ortions f. These portions f then repel the co or, while the pic- The surfaces 7) will take up printing ink,

ture surfaces 6 take up the color and Operate as printing elements.

In such plates it is, however, necessary to renew the amalgamated portions 0 (see Figure 1) and/or the amalgamated portions f (see Figure 3) by adding mercury to the printing plates, whereby the amalgamation again becomes freshened.

This is not accomplished, however, by merely applying the mercury in metallic condition to the printing ink, but it is necessary that the mercury be applied in extremely finely divided form, that is, in atomized condition, to the color, however, not before the actual printing process but during the printing process. Therefore, the finely divided mercury is added to the color not in the color container, but to'the color which is upon the rolls. However, upon the rolls the color lies in a very thin layer, and the mercury dust therefore cannot penetrate deeply into the color, because of its specific weight, inasmuch as only a thin layer of color is present, and furthermore the centrifugal force of the rotating rolls holds the mercury upon the surface, so that upon applying the color from the color roll to the printing plate, it is freely forced out between the color roll and printing plate, and can become placed upon the amalgamated portions and freshen them. The accompanying Figure 4 shows the rotary drum 7 of the printing machine upon which the printing plates at are clamped. h are the color rolls, to which for example the mercury is transferred in finely divided condition from a container 2'. At the points 71 then the mercury dust held upon the surface of the rolls h will be forced off upon the printing plates a.

I claim:

1. A process for the purpose described wherein the mercury forming the ink-repelling material of the rinting plate is continually renewed during the inking of the Iplate, consisting in applying the mercury in nely divided form to the printing ink while such ink is on the inking roll.

2. A process for the purpose described wherein the mercury forming the ink-repelling material of the printing plate is continually renewed during the in ing of the plate, consisting in applying the mercury in finely divided form to the printing ink while such ink is on the inking roll.

In testimony whereof he afiixes his signature.

HEINRICH RENCK. 

